I think this video is a good look at the book. The video is mainly positive and hightlights some things about the book that I overlooked originally. It also mentions how this book isn't really a good introduction to the Ravnica setting, which might be why I flipped through it and havent really looked at it that much since. This video made me want to take another look

The big problem I have with Ravnica is wondering where they get their food from. The whole world's a city? You have to have some farmers somewhere to grow your food.

The Drow can survive and grow food underground in complete darkness.

I think surface dwellers can easily survive. Roof gardens are very fashionable these days in Cuba. Also many local parks were transformed into vegetable plantations after what they call the «Special Period» when they ran out of food because the soviets decided not to support them anymore.

The big problem I have with Ravnica is wondering where they get their food from. The whole world's a city? You have to have some farmers somewhere to grow your food.

I believe there are some rooftop gardens, mostly run by the Selesnya and Simic, which would provide most of the fancy expensive food for the rich influential people. But feeding the 99% is pretty much entirely the responsibility of the Golgari, having been codified as such in the Guildpact, and the fact that they do that is pretty much why the other guilds tolerate the Golgari, instead of treating them as just a creepier and grosser version of the Gruul. The Golgari feed the city's poor people all sorts of fungus and "recycled protein" and such, produced very cheaply and in mass quantities in the Undercity, and I'd imagine that even when they're at war with another guild, they still keep up this duty, at least in areas not controlled by their enemy. (As an aside, the Rakdos kind of do a similar thing to provide "spiritual nourishment", in the form of entertainment, to keep the people content; the Golgari are the bread, the Rakdos are the circuses, and the Azorius are the Roman authorities, who work with the despised Golgari and Rakdos because they keep the population in line.)